DIY Electric Car Forums banner

1 - 1 of 1 Posts

·
Registered
Joined
·
70 Posts
Discussion Starter · #1 ·
Re: [EVDL] Converting from watt-hours/mi. to mi/gal & back

Peter VanDerWal <[email protected]> wrote:
> It's not that easy.
>
> It's not a this equals that formula.
>
> You have to take into account the efficiency of the ICE and the efficiency
> of the EV drive system.

No, you don't. That's the point: the comparison of power in per mile
*is* a comparison of the overall efficiencies of the ICE vs. EV. Not
just motor efficiency vs. engine efficiency, but also including drag
and mechanical friction. Using the direct conversion factor, you are
looking at how much energy you put into the car to travel one mile.
Not how much of the energy is actually used by the car (factoring in
efficiency), but how much you have to put in.

With the ICE at 32 mpg, you put in 36 kWh and you travel 32 miles,
giving you about 1100 Wh/mile.

With an EV, you put in 300 Wh of electricity and you drive a mile. The
EV thus takes 300 Wh/mile.

-Morgan

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
 
1 - 1 of 1 Posts
Top